Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Name the causative organism of the disease amoebiasis. List three symptoms of the disease.

Mention a product of human welfare obtained with the help of each one of the following microbes :
(a) LAB
(b) Saccharomyces cerevisiae
(c) Propionibacterium shermanii
(d) Aspergillus niger

Choose any three microbes, from the following which are suited for organic farming which is in great demand these days for various reasons. Mention one application of each one chosen.

Mycorrhiza, Monascus, Anabaena, Rhizobium, Methanobacterium, Trichoderma.

Since October 02, 2014 "Swachh Bharat Abhiyan" has been launched in our country.
(a) Write your views on this initiative giving justification.
(b) As a biologist name two problems that you may face while implementing the programme in your locality.
(c) Suggest two remedial methods to overcome these problems.

List the symptoms of Ascariasis. How does a healthy person acquire this infection?

Why is Gambusia introduced into drains and ponds?

What are the various public health measures, which you would suggest as safeguard against infectious diseases?

How does the transmission of the following disease take place?

Amoebiasis

What would be the molar concentration of human DNA in a human cell?

Distinguish between Plasmid DNA and chromosomal DNA

Distinguish between RNA and DNA

Does our blood have proteases and nucleases?

Name the three important components of biodiversity.

The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?

List all the wastes that you generate, at home, school or during your Trips to other places, could you very easily reduce? Which would be Difficult or rather impossible to reduce?

Match the items given in column A and B:

What measures, as an individual, you would take to reduce environmental pollution?

Explain the role of Restriction endonuclease in Biotechnology

Explain the role of the Gel − electrophoresis in Biotechnology

Explain the role of the Selectable markers in pBR322 in Biotechnology.